# Strength of gravity

1. Oct 8, 2007

### physstudent1

1. The problem statement, all variables and given/known data

The strength of gravity on the moon is 1/6 of that on earth. If a ball is thrown straight upward on the moon with initial velocity Vo the ratio of the height it reaches to the height it would reach on earth, if also thrown upward with velocity Vo is:

2
1/6
6
depends on Vo
36

2. Relevant equations

3. The attempt at a solution
EDIT: I got 6 I want to know if this is correct because it is a review question for an exam I have in an hour. Can someone help me out? I solved 2 kinematic equations with Vo with the only knowns being the gravity acclerations and got x on earth = Vo^2 / (2g) and x on the moon to be = 6Vo^2 / (2g)

Last edited: Oct 8, 2007
2. Oct 8, 2007

### G01

While the distances the ball travels upward on either the earth or the moon will depend on V_o, the ratio of them will not.

Try to set up an equation of motion for each situation. Using the two equations you should see that you can find an equation for the ratio that is not dependent on V_o.

3. Oct 8, 2007

### physstudent1

right I did an edit to show I got 6 is that correct?

4. Oct 8, 2007

Correct.